11/18/2016Basic TCP/IP Networking 1 TCP/IP Overview Basic Networking Concepts

11/18/ What is TCP/IP? TCP/IP is a name refers to an entire collection of data communication protocols: TCP: Transmission Control Protocol IP: Internet Protocol ICMP: Internet Control Message Protocol...

11/18/ TCP/IP Features ● Open protocol standards ● Independence from specific physical network hardware ● Ethernet ● Token ring ● Dial-up line ● X.25 net … ● A common addressing scheme ● Standardized high-level protocols

11/18/ Topics of Discussion ● Data Communication Model ● TCP/IP Protocol Architecture ● TCP/IP Layers ● Major TCP/IP procotols in each Layer

11/18/ Data Communication Model

11/18/ TCP/IP Protocal Architecture

11/18/ Application Layer The Application Layer is the level of the protocol hierarchy where user-accessed network processes reside. In TCP/IP, this refer to any network process that occurs above the Transport Layer. This includes all of the processes that users directly interact with, as well as other processes at this level that users are not necessarily aware of.

11/18/ Transport Layer The Transport Layer guarantees that the receiver gets the data exactly as it was sent. In TCP/IP this function is performed by the Transmission Control Protocol (TCP). TCP/IP also offers a second Transport Layer service, User Datagram Protocol (UDP), that does not perform the end-to-end reliability checks.

11/18/ Network Layer The Network Layer manages connections across the network and isolates the upper layer protocols from the details of the underlying network. In TCP/IP, the Internet Protocol (IP) is used in the Network Layer

11/18/ Data Link Layer The reliable delivery of data across the underlying physical network is handled by the Data Link Layer. TCP/IP rarely creates protocols in the Data Link Layer. Most RFCs that relate to the Data Link Layer discuss how IP can make use of existing data link protocols

11/18/ Physical Layer The Physical Layer defines the characteristics of the hardware needed to carry the data transmission signal. Features such as voltage levels, and the number and location of interface pins, are defined in this layer. Examples:RS232C and V.35, IEEE TCP/IP does not define physical standards - it makes use of existing standards.

11/18/ TCP/IP Protocol Architecture ● 3 to 5 functional levels ● Data Encapsulation ● Headers ● Data

11/18/ TCP/IP Data Encapsulation

11/18/ Data Structures

11/18/ Data Link and Physical Layer ● The lowest layer ● Protocols in this layer provide the means for networking device to deliver data to the other devices on a directly attached network. ● Protocols in this layer are hidden to the users ● IP (logical network) addresses are converted into physical (network) addresses ● e.g. ARP – address resolution protocol

11/18/ Network Layer ● Internet Protocol (IP) ● IPv4 and Ipv6 (connectionless protocol) ● Defines the datagram – basic unit of transmission ● Defines the Internet addressing scheme ● Moves data between Network access layer and the Transport layer ● Routes datagrams to remote hosts ● Performs fragmentation and re-assembly of datagrams

11/18/ IP Datagram Format

11/18/ Routing

11/18/ Network Layer – ICMP Internet Control Message Protocol provides: ● Flow control ● unreachable destinations detection ● Routes redirection ● Remote hosts status checking

11/18/ Transport Layer ● Transmission Control Protocol (TCP): ● Reliable data delivery with positive acknowledgment with retransmission ● Connection-oriented ● Three-way handshake ● User Datagram Protocol (UDP) ● Minimum protocol overhead (unreliable) ● Connectionless

11/18/ Application Layer Application Protocols: ● HTTP – Hypertext Transfer Protocol ● SMTP – Simple Mail Transfer Protocol ● DNS – Domain Name Service ● FTP – File Transfer Protocol ● Telnet – Network Terminal Protocol ● NFS – Network File System ● NIS – Network Information System